It doesn't make sense to have a maximum number of chunks smaller than
the initial number of chunks attached to the context.
Fix the uAPI header to reflect the new constraint, and mention the
undocumented "initial_chunk_count > 0" constraint while at it.
v3:
- Add R-b
v2:
- Fix the check
Fixes: 9cca48fa4f89 ("drm/panthor: Add the heap logical block")
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Reviewed-by: Liviu Dudau <liviu.dudau@xxxxxxx>
Reviewed-by: Steven Price <steven.price@xxxxxxx>
---
drivers/gpu/drm/panthor/panthor_heap.c | 3 +++
include/uapi/drm/panthor_drm.h | 8 ++++++--
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/panthor/panthor_heap.c b/drivers/gpu/drm/panthor/panthor_heap.c
index c3c0ba744937..3be86ec383d6 100644
--- a/drivers/gpu/drm/panthor/panthor_heap.c
+++ b/drivers/gpu/drm/panthor/panthor_heap.c
@@ -281,6 +281,9 @@ int panthor_heap_create(struct panthor_heap_pool *pool,
if (initial_chunk_count == 0)
return -EINVAL;
+ if (initial_chunk_count > max_chunks)
+ return -EINVAL;
+
if (hweight32(chunk_size) != 1 ||
chunk_size < SZ_256K || chunk_size > SZ_2M)
return -EINVAL;
diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h
index dadb05ab1235..5db80a0682d5 100644
--- a/include/uapi/drm/panthor_drm.h
+++ b/include/uapi/drm/panthor_drm.h
@@ -895,13 +895,17 @@ struct drm_panthor_tiler_heap_create {
/** @vm_id: VM ID the tiler heap should be mapped to */
__u32 vm_id;
- /** @initial_chunk_count: Initial number of chunks to allocate. */
+ /** @initial_chunk_count: Initial number of chunks to allocate. Must be at least one. */
__u32 initial_chunk_count;
/** @chunk_size: Chunk size. Must be a power of two at least 256KB large. */
__u32 chunk_size;
- /** @max_chunks: Maximum number of chunks that can be allocated. */
+ /**
+ * @max_chunks: Maximum number of chunks that can be allocated.
+ *
+ * Must be at least @initial_chunk_count.
+ */
__u32 max_chunks;
/**
--
2.44.0
